I would experiment with the liquid embroidery paint before doing anything "good". Be sure to shake it up well before using.
It's been years since I had mine, but I made pillowcases for the boys when they were little. Think they must have gotten passed on to new homes about 30 years ago when the guys got be teenagers. The pillowcases were washed frequently (at least every week) and the colors held up well.
I still have a little wallhanging that I had originally made for my MIL back then.